Yeah, any FM detector has a DC output shift caused by FM.Nigel Goodwin said:A simple FM detector will output different voltages for the two carrier frequencies, and you can easily convert it to logic levels with a comparator.
Even the AM receiver used by MStechca can have a DC output shift if it slope-detects the FM.
Then the data can't have a string of highs nor lows. Therefore is their data coding called "Manchester" or "NRZ"?Many licence free modules use FSK, but they use AC coupling, which prevents a continuous DC output from the receiver.